Analysis and Control of the Initial Electrodeposition Stages of Co-Pt Nanodot Arrays
Analysis and Control of the Initial Electrodeposition Stages of Co-Pt Nanodot Arrays
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Co-Pt 纳米点阵列电沉积初始阶段的分析与控制
DOI：
10.1016/j.electacta.2015.11.136
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
T. Homma
中科院分区：
文献类型：
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作者：
S. Wodarz;J. Abe;T. Homma
我们利用电沉积与电子束微影技术相结合的方法，制备出Co-Pt奈米点阵列，以应用于超高密度磁记录媒体，例如位元图案化媒体（BPM）。在这项工作中，我们分析了初始成核和生长的Co-Pt纳米孔内实现纳米点阵列具有高沉积均匀性，以及磁性能。在-900 mV（vs. Ag/AgCl）下，大小为2.0-3.0 nm的多个核随机分布，甚至在直径为10 nm的纳米孔中也是如此，这可能导致磁性缺乏均匀性。然后通过施加较小的负电位（>-700 mV vs. Ag/AgCl）以在每个纳米孔内存款单个核来减少核的数量。结果，尺寸为5.0-10 nm的单个晶粒成功地沉积在纳米孔内，这可以在每个纳米点中诱导均匀的磁性。另外，在较低的负电位下，Co-Pt薄膜的电阻率增加，这是由于Co-Pt在Ru衬底上的类外延生长所致。横截面TEM分析表明，以较小的负电位沉积的Co-Pt是单晶，在垂直于Ru界面的方向上具有均匀的hcp晶格条纹，表明形成了具有高垂直磁各向异性的高度均匀的纳米点阵列。
We have fabricated Co-Pt nanodot arrays by combining electrodeposition with electron beam lithography (EBL) for applications in ultra-high density magnetic recording media, such as bit-patterned media (BPM). In this work, we analyzed the initial nucleation and growth of Co-Pt inside nanopores to achieve nanodot arrays with high deposition uniformity, as well as magnetic properties. At −900 mV (vs. Ag/AgCl), multiple nuclei of 2.0–3.0 nm in size were randomly distributed, even in nanopores with a 10 nm diameter, which could result in a lack of uniformity in the magnetic properties. The number of nuclei was then reduced by applying a less negative potential (>−700 mV vs. Ag/AgCl) to deposit a single nucleus inside each nanopore. As a result, a single grain of 5.0–10 nm in size was successfully deposited inside the nanopore, which could induce uniform magnetic properties in each nanodot. In addition, at less negative potentials, the coercivity of the Co-Pt films increased, which was induced by the epitaxial-like growth of Co-Pt from the Ru substrate. Cross-sectional TEM analysis suggested that Co-Pt deposited with a less negative potential was single crystalline with uniform hcp lattice fringes in the direction perpendicular to the Ru interface, indicating the formation of highly uniform nanodot arrays with high perpendicular magnetic anisotropy.